This lens is amazingly sharp. It's as sharp as my 24-70mm II 2.8 if not sharper. When sharpness counts and bokeh doesn't matter, this is the lens to get. I don't have a 50mm 1.2L, but comparing images I've seen, the sharpness is definitely in par. Fantastic for museums and art galleries.

I have this lens for the Canon body. Focus is not fast, but very usable. The optics is lacking when compared to any 50mm prime Canon offers. In other words, it's sharp, but not that great. It's okay for the price if you need a wider range. It's macro, but you can't focus that close. Could use some better build quality, feels a little flimsy.

HOWEVER, it's fantastic for DSLR videos. That was the reason I got it. The huge focus ring, focus distance indicator, and its light weight is great.

Positives:
I purchased this camera as a refurb from Canon a while back, and it was a great bargain, at only $50 more than a t4i.

Construction is much more solid than my previous rebel—it's not heavy, but feels fantastic in the hand. the shutter and aperture dials are also very convenient, as most canon dslr's are.

The battery is very good. Once, I accidentally forgot to turn the camera off for a little over 3 weeks. But after the 3 weeks, the camera still had half battery left. When shooting, I can go the entire day without the battery indicator moving a bit (I turn flip the screen inside, and only use the top panel LCD).

Autofocus is fast with the right lens, but only 9 points.

Negatives:
At high ISO, the camera is a bit disappointing. Anything over ISO 400 I think is too noisy.

Very sharp little lens. Has the metal mount instead of plastic mount on the mark ii. I felt it's even sharper than 50mm 1.4, but that might just be my copy. Build quality wise, it's not flimsy, but seems that it could break with a small drop, but I've never tested that... It's an awesome lens for film too, since it has the zoom ring.

Image quality and color wise, this lens produces images as best as the digital slr format can take. Just as a comparison between the common 50mm 1.8, it's about the same in sharpness at f/4 (maybe a tad sharper) but much better in color. When I shoot digital (or 35mm), it's on my camera 90% of the time. Some people say that because it is plastic, the build quality is not as good as the mark i. But it's much lighter than the mark i, and I think it's definitely very solidly built. Didn't find the lack of IS a huge deal breaker, as I usually carry a tripod or monopod.